Breakthrough discovery gives new hope for treating macular degeneration

2012-04-08 22:09
Breakthrough discovery could help prevent common cause of blindness.

Scientists have made a major breakthrough in understanding how prevent Age Related Macular Degeneration (AMD) by controlling an inflammatory factor in the body called inflammatory component IL-18.

The disease makes it difficult to see out of the center of the eye because it causes yellowish/white deposits in the middle of the retina, obscuring vision. The middle of the retina is called the macula.

There is no therapy to treat the disease once it happens. The deposits in the eye are characteristic of ‘dry macular degeneration’ that often progresses to “wet” macular degeneration.

Progression of dry to wet AMD causes blood vessels begin to proliferate underneath the retina, leading to blindness.

Symptoms of the eye disease, which should be evaluated immediately, include straight lines appearing wavy, objects look further away or closer than they are, and doorways may appear crooked.

Over 200,000 people in the United States are diagnosed with wet macular degeneration each year.

Risk factors for the disease include smoking, being over age 60, female and family history. Caucasians are more prone to AMD than are other ethnicities. Other risk factors include hypertension and obesity.

Dr Sarah Doyle and Dr Matthew Campbell from Trinity College Dublin have published their findings in the journal Nature Medicine that drusen – the yellow/white deposits that accumulate in the macula - can lead to the production of two inflammatory components termed IL-1beta and IL-18.

Component identified that prevents AMD progression

"Traditionally, inflammation in the retina or indeed the eye in general is not beneficial and is a pathological hallmark of many eye diseases, including AMD. However we have identified, that one inflammatory component termed IL-18 acts as a so-called anti-angiogenic factor, preventing the progression of wet AMD" says Dr. Campbell in a media release.

Doyle further explains, "The progression from "dry" to "wet" AMD appears to be mediated by the inflammatory component IL-18, our results directly suggest that controlling or indeed augmenting the levels of IL-18 in the retinas of patients with dry AMD could prevent the development of the wet form of disease, which leads us to an exciting new prospect for a novel therapy for AMD.”

The finding is a breakthrough because there is no cure for age-related macular degeneration. Antioxidants and zinc are believed to slow the progression of the dry form of AMD. Wet macular degeneration is treated by trying to slow the growth of blood vessels with anti-VEGF drugs that are available. The study identifies the inflammatory component IL-18 as a possible treatment for AMD. Boosting levels of the inflammatory compound could lead to prevention of blindness from the eye disease.

Source
Nature Medicine
doi:10.1038/nm.2717
“NLRP3 has a protective role in age-related macular degeneration through the induction of IL-18 by drusen components”
Sarah L Doyle, et al

Resources:
AMDawareness.org

Image credit: Wikimedia commons

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